Array Formula - calculating results on a rolling basis

Hi,

I have in A1:A1000 a series of numerical values. In column B, from B3 onwards, there is a formula in each cell that calculates the compounded value of the 3 previous values in column A using the following formula:

e.g. {=(product(1+A1:A3/100)-1)*100} in B3

In B4 the formula would be {=(product(1+A2:A4/100)-1)*100} etc

Finally I calculate the average of the values in column B.

Instead of using the “helper” column B as described above, is it possible to create a single array formula that calculates from the data in column A each of the compounded values, as in column B, and returns the average of the results?

Thanks!